Consider this: How could anyone other than Murphy and his agent know who the 'frontrunner' is? And what benefit is there to Murphy and his agent (really answer this) to tell one specific team they are the frontrunner. If I were them, I'd want multiple teams to think they have a shot at landing him. It would not be a smart bargaining position to tell a team prematurely -- 'I want to play for you'. What you want is to keep multiple teams in the mix to drive up the interest and price.
I give all the reports on 'frontrunner' limited credibility unless directly from Murphy or his agent.